Fluid control apparatuses for use in semiconductor fabrication equipment have been increasingly integrated by installing lines each having a plurality of fluid control devices in series that are attached to a support on a base in parallel without interposing pipes and joints thereamong. Patent Literature 1 discloses such a fluid control apparatus having an upper stage and a lower stage. The upper stage has a plurality of lines arranged in parallel. Each of the line has a plurality of fluid control device arranged in series. The lower stage has a plurality of passage blocks that connect the fluid control devices on the upper stage.
FIG. 12 shows a conventional fluid control apparatus, which is a target for improvement to be made by the present invention. FIG. 12 shows one line having an upper stage and a lower stage. The conventional fluid control apparatus has a plurality of such lines arranged in parallel.
The conventional fluid control apparatus has a plurality of fluid control devices arranged on the upper stage. The fluid control devices include, from the left (from the inlet side), a third inlet-side on-off valve 91, a pressure regulator 92, a filter 93, a first inlet-side on-off valve 94, a second inlet-side on-off valve 95, a mass flow controller 96, and a first outlet-side on-off valve 97. The third inlet-side on-off valve 91 is connected to a process gas supply pipe 103.
The mass flow controller 96 includes a body 96a, an inlet extension 96b, and an outlet extension 96c. These extensions 96b, 96c are disposed on the opposite side surfaces of the mass flow controller body 96a. 
Each of the fluid control devices 91, 92, 93, 94, 95, 96, 97 has a passage with a downward opening. These passages are connected to a plurality of block joints (or passage blocks) with various shapes that are arranged on the lower stage, respectively. These block joints (passage blocks) in the conventional fluid control apparatus includes six block joints 99, a block joint 100, and a block joint 101. Each of the block joints 99 has a V-shaped passage. The block joints 99 connect respective adjacent fluid control devices 91, 92, 93, 94, 95, 96b, 96c, 97. The block joint 100 is disposed between two block joints 99 each having a V-shaped passage 99a and supports the second inlet-side on-off valve 95. The block joint 101 has a pipe joint 101a and supports an outlet end of the first outlet-side on-off valve 97.
The block joint 100 disposed between the two block joints 99 that supports the second inlet-side on-off valve 95 and the block joint 101 that supports the outlet end of the first outlet-side on-off valve 97 are both disposed over all the plurality of lines (the block joints 100, 101 are also referred to as “manifold block joints”). As for the block joints 99, different lines have different components. The manifold block joint 100 is usually used as a purge gas line. The manifold block joint 101 is usually used as a process gas line and a purge gas line.
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2002-349797